Boeing has identified a software issue in some 737 MAX aircraft that could result in the automated flight guidance system disengaging after a missed landing approach, and is working on a permanent software fix, the aircraft maker said.
The issue can arise following a missed approach when a pilot changes the preprogrammed flight path, according to Boeing.
In such a situation, the flight management computer software may cause the aircraft to transition from a vertical navigation mode to a simpler level of automation for pitch control.
If the transition occurs, pilots would need to perform additional procedural steps if they want to use automated vertical navigation on subsequent approaches, Boeing said.
"Last month, we informed all 737 operators about a software issue where pilots may experience a reduction in automation during a landing scenario. We shared information with operators that reinforced existing pilot procedures for safely handling such cases," a Boeing spokesperson said in a statement.
The company said it had informed the US Federal Aviation Administration (FAA) about the issue as part of its safety review process and was working under the regulator's oversight to complete the software update.
Boeing is also working directly with airlines to formalise a procedure that would allow pilots to re-enable automated vertical navigation if the situation occurs.
"All pilots are trained to safely land an airplane without automated vertical navigation," the spokesperson said, stressing that existing pilot training covers landing an aircraft without the automated system.
In India, Air India Express and Akasa Air together operate around 96 Boeing 737 MAX aircraft. Air India Express has around 53 planes, while Akasa Air operates 43.
Akasa Air said it was coordinating with Boeing and that the issue had no impact on the safety of its operations.
"We are closely coordinating with Boeing and can confirm that there is no impact to the safety of Akasa Air operations.
"Our aircraft continue to operate safely in accordance with established procedures and applicable regulatory requirements," an airline spokesperson told PTI in a statement.
The carrier did not specifically say whether any of its Boeing 737 MAX aircraft had been affected by the issue.
There was no response from Air India Express.
There was no immediate response from the Directorate General of Civil Aviation (DGCA) on whether it was looking into the issue or issuing any advisory to airlines.
Globally, Boeing has delivered more than 2,400 737 MAX aircraft to airlines.
The development comes after Airbus earlier this week identified a quality issue with the surface protection coating on the fuselage of a significant number of narrow-body A321neo aircraft. Around a dozen such aircraft operated by IndiGo are also affected, according to sources.
IndiGo and Air India operate A321neo aircraft, with around 190 such planes between them.
(With inputs from PTI and ANI)
